Save energy today with our easy-to-fit . CleverSpa Universal Thermal Insulation Hot Tub Cover ?C Medium Round that will immediately improve your Hot Tub’s heat retention due to the thermal insulation making it up to 50% more energy efficient! With improved energy efficiency . using your Inflatable Hot Tub all year round couldn’t be easier and is now more viable. FITS ALL BRANDS OF INFLATABLE HOT TUBS UP TO 81 INCHES IN DIAMETER!Our CleverSpa Thermal Cover is waterproof to HH 118 inches (3000 mm) . as well as UPF 50+ providing protection from extreme weather conditions.Our CleverSpa Universal Medium Round 81 in Thermal Cover is compatible with any Round . 6 Person Lazy Spa & Wave Spa Hot Tub.NOTE:The CleverSpa Universal Hot Tub Thermal Insulation Cover is packaged inside out. Turn the correct way around . placing the logos on top to ensure the thermal cover is waterproof. Exposure to direct sunlight will cause the Universal Thermal Hot Tub Cover to fade over time.